That's great advice, a couple other things.
{{hugs}}
Is it possible that your little sweetie is going through a growth spurt. I'm pretty sure there's one right around there.
Pumping after you feed is great. I think the suggested amount of time is 15 minutes. It doesn't matter if you are getting anything, it's sending a signal to your brain to produce more.
It seems silly to say, but make sure you are drinking lots of water and are getting plenty of rest.
And trust me, it is only going to get easier from here on in. Keep up with the bfing and I'm certain very shortly you are going to wonder why mamas go to all the work of doing up bottles. Bfing just seems so much easier to me now.
I always feel deflated now. I never really felt full, but I did notice around the 4 month mark that I was always deflated. lol It's quite common for women to stop feeling full. Don't stress that one bit, that's common.
Try not to supplement with a bottle, that is only going to diminish your supply. Make sure the bottle nipple you are using is slow flow so he has to work hard to get that milk out.... or else he may get lazy and not want to work when he nurses. If he gets hungry again, offer to bf. It may encourage snacking, but it's better then supplementing with a bottle. You can eventually stretch things back out if he becomes a snacker.
Hope this helps.
Hugs again.